Cleared codes on my LS2 then on restart when temp reaches 94C code 101 and 174 come back.Checked MAF at idle 6.42g/s
long term ft bank 1 24%
long term ft bank 2 24%
engine speed 795 rpm
spark 13
HO2S Bank1 sensor 2 120 mV
distance since dtc cleared 56 km
BARO 101 kPa
my tech is stumped car is running great but codes keep coming back. did test for leaks.o2 sensors are not the problem.Need help with this one.

 

I vote big vacuum leak.

If it is large enough it may start throwing MAF codes. Even small vacuum leaks will cause lean codes.

Any recent modes before this started?

You may also want to try cleaning your MAF. Gunk on the MAF will cause codes and MAF codes as well.